StudyLow-dose naltrexone2020

Raknes 2020: low-dose naltrexone and thyroid medicine use in Norway

Raknes G, Småbrekke L. No change in the consumption of thyroid hormones after starting low dose naltrexone (LDN): a quasi-experimental before-after study

What it found

Starting low-dose naltrexone was not linked to any change in how much thyroid hormone 898 Norwegians with hypothyroidism were dispensed in the following year. If anything, levothyroxine use tended to rise with more LDN use, so the study doesn't support claims that LDN helps hypothyroidism.

People with hypothyroidism who started LDN: 898

What they tested

Low-dose naltrexone (LDN) is reported to help several autoimmune diseases, and some people take it for an underactive thyroid (hypothyroidism). Using the Norwegian Prescription Database, researchers identified 898 people with hypothyroidism who started LDN.

They compared the amount of thyroid hormone dispensed, both T3 (triiodothyronine) and LT4 (levothyroxine), and the number of users in the year before and the year after the first LDN prescription. People were split into three groups based on how much LDN they used.

What they found

There was no association between starting LDN and later dispensing of thyroid hormones.

If anything, levothyroxine (LT4) use tended to increase as LDN exposure increased.

Limits

It counted prescriptions dispensed, not thyroid blood tests or symptoms.
There was no randomized comparison group. It compared the same people before and after starting LDN.
The abstract doesn't report the size of the changes in each group.

What it means if you're considering naltrexone

If LDN improved an underactive thyroid, people might need less thyroid hormone after starting it. This study didn't see that. It doesn't rule out effects on how people feel, but it gives no support to the idea that LDN treats hypothyroidism.

Frequently asked questions

Does low-dose naltrexone help hypothyroidism?

This Norwegian study of 898 people found no change in thyroid hormone use after starting LDN, and the authors say their results don't support claims that LDN works for hypothyroidism.

The paper

Raknes G, Småbrekke L. No change in the consumption of thyroid hormones after starting low dose naltrexone (LDN): a quasi-experimental before-after study. BMC Endocr Disord. 2020;20(1):151. doi:10.1186/s12902-020-00630-4

Read the paper doi:10.1186/s12902-020-00630-4

We wrote this page from the paper's published abstract, and the study's numbers here come from there. Updated October 17, 2026.

Medical disclaimer

This page is for information only and is not medical advice, diagnosis, or treatment. Don't start, stop, or change any medicine — including naltrexone — without your prescriber. Naltrexone must not be used by people taking opioid pain medicines, people dependent on opioids, or people in opioid withdrawal (FDA label). In an emergency call 911; for crisis support call or text 988. Full medical disclaimer.